Thermal Strain and Temperature Measurements of Structures Using Fiber - Optic Sensors

KITSAT-3 satellite loaded the GPS receiver for the purpose of performance test. GPS navigation solutions, which consist of position and velocity components, are calculated in on-board system and are transferred from KITSAT-3 to ground station by telemetry. In this study, The GPS navigation solutions of KITSAT-3 were compared with the results of TLE/SGP4 orbit propagator which is used in KITSAT-3 tracking system and then the differences between them were analyzed. The KITSAT-3 orbit was determined using GPS navigation solutions as observation data on the base of precise perturbation model. YSODSv2 orbit determination system that had been developed by Center for Astrodynamics in Yonsei university was used for the precise orbit determination. In the process of orbit estimation, the position components of GPS navigation solutions were inputted as observational data and Bayesian least square method was applied. Since KITSAT-3 GPS navigation solutions include the large errors and in particular the error of velocity components is the larger than that of position components, it is improper to utilize them in the tracking system. But in the KITSAT-3 mission, TLE/SGP4 algorithm can be replaced by the orbit determination system using CPS navigation solutions.